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000 

WWUS20 KWNS 252146

SEL1

SPC WW 252146

IAZ000-MNZ000-WIZ000-260400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 751

NWS STORM PREDICTION CENTER NORMAN OK

445 PM CDT FRI JUL 25 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST IOWA

       EXTREME SOUTHEAST MINNESOTA

       SOUTHWEST AND SOUTH CENTRAL WISCONSIN



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 445 PM UNTIL

1100 PM CDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES SOUTHWEST

OF ROCHESTER MINNESOTA TO 50 MILES EAST OF CAMP DOUGLAS

WISCONSIN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



OTHER WATCH INFORMATION...CONTINUE...WW 749...WW 750...



DISCUSSION...STRONG SURFACE TROUGH/WIND SHIFT SPREADING SEWD ACROSS

WRN WI THIS AFTERNOON IS ASSOCIATED WITH MID/UPPER WAVE OF MODERATE

STRENGTH. LIFT ACCOMPANYING THESE FEATURES WILL AT LEAST SUSTAIN

ONGOING TSTMS AND COULD PROMOTE ADDITIONAL DEVELOPMENT GIVEN PERIOD

OF MAXIMUM DIURNAL DESTABILIZATION. IN FACT...FORCING IS DEVELOPING

INTO AN AXIS OF GREATER SURFACE-BASED INSTABILITY FROM NERN IA INTO

SWRN WI ATTM. INCREASING WNWLY MID LEVEL FLOW OF 40-45 KT ATOP

GENERALLY WEAKER WLY FLOW IN THE BOUNDARY LAYER SHOULD RESULT IN

SUFFICIENT EFFECTIVE SHEAR FOR A FEW ORGANIZED STORMS TO PERSIST

INTO THE EVENING HOURS. HAIL AND LOCALLY DAMAGING WINDS APPEAR

POSSIBLE WITH THIS ACTIVITY.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. MEAN STORM

MOTION VECTOR 29030.





...CARBIN

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